Lipid-rich fat sources such as poultry fats and other animal fats, poultry meal and other animal meals, vegetable oils, fish oils, yellow grease, and fish meals are commonly included in a variety of foods for human consumption, animal feeds, and nutritional supplements for both humans and animals. Although these fat sources are energy-rich nutritional compounds and may further possess useful therapeutic properties as in the case of polyunsaturated fatty acids, the fat sources are vulnerable to a number of environmental and structural factors during manufacturing and storage that may reduce their efficacy or possibly render them unusable. In particular, many lipid-rich fat sources may undergo undesired oxidation due to exposure to air, light, internally generated free radicals, and trace metals.
In order to stabilize lipid-containing oils and fat products, potent synthetic antioxidants such as ethoxyquin, TBHQ, BHT, or BHA may be added, but the consumption of synthetic antioxidants may lead to negative health effects. Alternatively, synthetic and natural antioxidants of low efficacy, such as mixed tocopherols, rosemary extracts, phosphoric acid, and propyl gallate may be added to inhibit oxidation. High concentrations of other natural compounds with modest antioxidant properties may also be added, including monosaccharides, polysaccharides, and fiber. The use of natural antioxidants may result in more healthful food and feed products, but product quality may suffer during manufacturing and storage due to the low efficacy of natural antioxidants.
A need exists in the art for a natural antioxidant composition that possesses an efficacy that is at least as high as the potent synthetic antioxidants and does not induce the adverse health effects of the synthetic antioxidants.